Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Uni-directional liquid spreading on asymmetric nanostructured surfaces

Abstract

Controlling surface wettability and liquid spreading on patterned surfaces is of significant interest for a broad range of applications, including DNA microarrays, digital lab-on-a-chip, anti-fogging and fog-harvesting, inkjet printing and thin-film lubrication1,2,3,4,5,6,7,8. Advancements in surface engineering, with the fabrication of various micro/nanoscale topographic features9,10,11,12,13, and selective chemical patterning on surfaces14,15, have enhanced surface wettability3,16,17 and enabled control of the liquid film thickness18 and final wetted shape19. In addition, groove geometries and patterned surface chemistries have produced anisotropic wetting, where contact-angle variations in different directions resulted in elongated droplet shapes20,21,22,23,24,25,26. In all of these studies, however, the wetting behaviour preserves left–right symmetry. Here, we demonstrate that we can harness the design of asymmetric nanostructured surfaces to achieve uni-directional liquid spreading, where the liquid propagates in a single preferred direction and pins in all others. Through experiments and modelling, we determined that the spreading characteristic is dependent on the degree of nanostructure asymmetry, the height-to-spacing ratio of the nanostructures and the intrinsic contact angle. The theory, based on an energy argument, provides excellent agreement with experimental data. The insights gained from this work offer new opportunities to tailor advanced nanostructures to achieve active control of complex flow patterns and wetting on demand.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Comparison of wetting behaviour on symmetric and asymmetric nanostructured surfaces.
Figure 2: Scanning electron micrographs with uniform arrays of asymmetric nanostructured surfaces.
Figure 3: Time-lapse images of uni-directional spreading of a liquid droplet.
Figure 4: Experimental results and the theoretical curves predicting uni-directional liquid spreading.

References

  1. Chiou, N.-R., Lu, C., Guan, J., Lee, L. J. & Epstein, A. J. Growth and alignment of polyaniline nanofibres with superhydrophobic, superhydrophilic and other properties. Nature Nanotech. 2, 354–357 (2007).

    Article  CAS  Google Scholar 

  2. Krupenkin, T. N., Taylor, J. A., Schneider, T. M. & Yang, S. From rolling ball to complete wetting: The dynamic tuning of liquid on nanostructured surfaces. Langmuir 20, 3824–3827 (2004).

    Article  CAS  Google Scholar 

  3. Wang, R. et al. Light-induced amphiphilic surfaces. Nature 388, 431–432 (1997).

    Article  CAS  Google Scholar 

  4. Cebeci, F. Ç., Wu, Z., Zhai, L., Cohen, R. E. & Rubner, M. F. Nanoporosity-driven superhydrophilicity: A means to create multifunctional antifogging coatings. Langmuir 22, 2856–2862 (2006).

    Article  CAS  Google Scholar 

  5. Garrod, R. P. et al. Mimicking a stenocara beetle’s back for microcondensation using plasmachemical patterned superhydrophobic–superhydrophilic surfaces. Langmuir 23, 689–693 (2007).

    Article  CAS  Google Scholar 

  6. Wang, J. Z., Zheng, Z. H., Li, H. W., Huck, W. T. S. & Sirringhaus, H. Dewetting of conducting polymer inkjet droplets on patterned surfaces. Nature Mater. 3, 171–176 (2004).

    Article  Google Scholar 

  7. Hiratsuka, K., Bohno, A. & Endo, H. Water droplet lubrication between hydrophilic and hydrophobic surfaces. J. Phys. Conf. Ser. 89, 012012 (2007).

    Article  Google Scholar 

  8. Extrand, C. W., Moon, S. I., Hall, P. & Schmidt, D. Superwetting of structured surfaces. Langmuir 23, 8882–8890 (2007).

    Article  CAS  Google Scholar 

  9. Quéré, D. Non-sticking drops. Rep. Prog. Phys. 68, 2495–2532 (2005).

    Article  Google Scholar 

  10. Őner, D. & McCarthy, T. J. Ultrahydrophobic surfaces. Effects of topography length scales on wettability. Langmuir 16, 7777–7782 (2000).

    Article  Google Scholar 

  11. Bico, J., Tordeux, C. & Quéré, D. Rough wetting. Europhys. Lett. 55, 214–220 (1999).

    Article  Google Scholar 

  12. Seemann, R., Brinkmann, M., Kramer, E. J., Lange, F. F. & Lipowsky, R. Wetting morphologies at microstructured surfaces. Proc. Natl Acad. Sci. USA 102, 1848–1852 (2005).

    Article  CAS  Google Scholar 

  13. Maritines, E. et al. Superhydrophobicity and super hydrophilicity of regular nanopatterns. Nano Lett. 5, 2097–2130 (2005).

    Article  Google Scholar 

  14. Dupuis, A., Léopoldès, J., Bucknall, D. G. & Yeomans, J. M. Control of drop positioning using chemical patterning. Appl. Phys. Lett. 87, 024103 (2005).

    Article  Google Scholar 

  15. Gleiche, M., Chi, L. F. & Fuchs, H. Nanoscopic channel lattices with controlled anisotropic wetting. Nature 403, 173–175 (2000).

    Article  CAS  Google Scholar 

  16. Wenzel, R. Resistance of solid surfaces to wetting by water. Ind. Eng. Chem. 28, 988–994 (1936).

    Article  CAS  Google Scholar 

  17. Vorobyev, A. Y. & Guo, C. Metal pumps liquid uphill. Appl. Phys. Lett. 94, 224102 (2009).

    Article  Google Scholar 

  18. Xiao, R., Chu, K.-H. & Wang, E. N. Multi-layer liquid spreading on superhydrophilic nanostructured surfaces. Appl. Phys. Lett. 94, 193104 (2009).

    Article  Google Scholar 

  19. Courbin, L. et al. Imbibition by polygonal spreading on microdecorated surfaces. Nature Mater. 6, 661–664 (2007).

    Article  CAS  Google Scholar 

  20. Zhang, F. & Low, H. Y. Anisotropic wettability on imprinted hierarchical structures. Langmuir 23, 7793–7798 (2007).

    Article  CAS  Google Scholar 

  21. Bico, J., Marzolin, C. & Quéré, D. Pearl drops. Europhys. Lett. 47, 220–226 (1999).

    Article  CAS  Google Scholar 

  22. Chen, Y., He, B., Lee, J. & Patankar, N. A. Anisotropy in the wetting of rough surfaces. J. Colloid Interface Sci. 281, 458–464 (2005).

    Article  Google Scholar 

  23. Chung, J. Y., Youngblood, J. P. & Stafford, C. M. Anisotropic wetting on tunable micro-wrinkled surfaces. Soft Matter. 3, 1163–1169 (2007).

    Article  CAS  Google Scholar 

  24. Kusumaatmaja, H., Vrancken, R. J., Bastiaansen, C. W. M. & Yeomans, J. M. Anisotropic drop morphologies on corrugated surfaces. Langmuir 24, 7299–7308 (2008).

    Article  CAS  Google Scholar 

  25. Drelich, J., Wilbur, J. L., Miller, J. D. & Whitesides, G. M. Contact angles for liquid drops at a model heterogeneous surface consisting of alternating and parallel hydrophobic/hydrophilic strips. Langmuir 12, 1913–1922 (1996).

    Article  CAS  Google Scholar 

  26. Gau, H., Herminghaus, S., Lenz, P. & Lipowsky, R. Liquid morphologies on structured surfaces: From microchannels to microchips. Science 283, 46–49 (1999).

    Article  CAS  Google Scholar 

  27. Tenhaeff, W. E. & Gleason, K. K. Initiated and oxidative chemical vapour deposition of polymeric thin films: iCVD and oCVD. Adv. Funct. Mater. 18, 979–992 (2008).

    Article  CAS  Google Scholar 

  28. Baxamusa, S. H., Im, S. G. & Gleason, K. K. Initiated and oxidative chemical vapour deposition: A scalable method for conformal and functional polymer films on real substrates. Phys. Chem. Chem. Phys. 11, 5227–5240 (2009).

    Article  CAS  Google Scholar 

  29. Alf, M. E. et al. Chemical vapor deposition (CVD) of conformal, functional, and responsive polymer films. Adv. Mater. 21, 1–35 (2009).

    Google Scholar 

Download references

Acknowledgements

The authors gratefully acknowledge financial support from the National Science Foundation (under Award EEC-0824328), the DARPA Young Faculty Award and the Northrop Grumman New Faculty Innovation Grant. The authors would also like to acknowledge the Intel Higher Education Grant for a generous computer donation, and the MIT Microsystems Technology Lab. The authors thank B. E. Polat from D. Blankschtein’s group for help with surface tension measurements, and especially, M. E. Alf and S. Baxamusa from K. K. Gleason’s group for the initiated chemical vapour polymer deposition, all in the Department of Chemical Engineering, MIT.

Author information

Authors and Affiliations

Authors

Contributions

All authors contributed to designing and conducting the experiments, model development and preparing the manuscript.

Corresponding author

Correspondence to Evelyn N. Wang.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 528 kb)

Supplementary Information

Supplementary Movie 1 (MOV 2072 kb)

Supplementary Infromation

Supplementary Movie 2 (MOV 2861 kb)

Supplementary Information

Supplementary Movie 3 (MOV 2732 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Chu, KH., Xiao, R. & Wang, E. Uni-directional liquid spreading on asymmetric nanostructured surfaces. Nature Mater 9, 413–417 (2010). https://doi.org/10.1038/nmat2726

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat2726

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing